Spring motors of various kinds have been proposed as power sources for vehicles and other apparatus since at least the late eighteen hundreds. Typically these devices have involved a number of flat spirally wound springs connected between a frame and a shaft to be driven. Multiple gear trains, clutches, ratchets and brakes have been shown to control the winding up of the springs and the controlled release of the stored energy to the shaft to be driven. Patents of this genre include Gephart U.S. Pat. No. 1,217,935; Sims U.S. Pat. No. 1,258,158; and Middlestetter U.S. Pat. No. 2,493,989.
To obtain enough stored energy large springs such as suggested in Williams U.S. Pat. No. 3,732,949 or multiple springs connected in parallel as in Black U.S. Pat. No. 3,945,453 have been used with their consequent requirement of a large force to wind up the springs. Electric motors geared to provide the necessary force have been suggested for the wind up job. All of the art known to applicant has required large amounts of apparatus and equipment leaving much to be desired in commercial application.
Applicant has solved many of the problems of the prior art by connecting a number of identical flat spirally wound springs in series about a shaft to be driven so as to eliminate the need for expensive and cumbersome gearing, clutches, and winding mechanisms. Energy is stored by winding the first spring in the series while stopping the unwinding of the last spring in the series. All the springs are wound equally in the series with a force equal to the force required to wind just one of the springs. The number of turns required to wind up the series of springs is directly proportional to the number of springs in the series.